Complete Momentum-Balance Analysis of Permeate Flux for Ultrafiltration in Hollow-Fiber Modules

The predicting equations for the declines of transmembrane pressure and permeate flux in hollow-fiber ultrafilters were derived from the complete momentum balance with the consideration of the rate of momentum transfer by convection, instead of simply applying Hagen-Poiseuille theory without the consideration of the effect of permeation on fluid flow, resulting in improved prediction. The assumption of laminar flow in the fiber tubes was examined.